Shock proof relay



y 1965 w. D. RYCKMAN ETAL 3,184,564

SHOCK PROOF RELAY Filed April 30, 1965 INVENTORS WILLIAM D. RYCKMAN,

WILLIAM R. CI'ESSUP BY ATTORNEY United States Patent "ice 3,184,564 SHOCK PROOF RELAY William D. Ryckman and William R. Jess-up, Ashehoro,

N.C., assignors to General Electric Company, a corporation of New York Filed Apr. 30, 1963, Ser. No. 276,928 7 Claims. (Cl. 200-87) This invention relates to electrical relays and in particular to sensitive relays which are shock proof, i.e., capable of withstanding substantial impacts without detrimental eliect upon the calibrated operation of the relay.

As the consumer use of electrical apparatus in the home has increased, the need for electrical appliance components capable of withstanding continued handling by inexperienced and often careless users has increased proportionately. This is particularly true with respect to portable appliances, or electrical control apparatus therefor, which are subject to substantial impacts during use.

Relays, and especially those having carefully calibrated pick-up or drop-out levels, are particularly susceptible to the abuses of everyday consumer use in that the magnetic core or frame element of the relay is generally of relatively soft metal of high permeability for use as an electromagnetic core. It is highly desirable to prevent any deformation of this frame element in that its proper arrangement with the armature and the conventional relay coil is essential to accurate nad predictable operation of the relay.

It is, therefore, one object of this invention to provide an improved relay capable of withstanding substantial impact forces without change in calibrated pick-up or drop-out levels.

It is another object of this invention to provide such a relay of compact construction designed for ease of assembly.

it is yet another object of this invention to provide a relay capable of providing accurate circuit control.

p In carrying out the objects of our invention in one form thereof, we provide an electrical relay having a chassis, a support member secured to the chassis, a frame and armature for forming a magnetic circuit, a coil arranged to produce an electromagnetic force in the frame, and a pair of relatively movable contacts. The magnetic frame and the coil are independently mounted from the chassis to prevent deformation of the frame by the mass of the coil upon impact against the relay. This independent mounting is accomplished by supporting the coil from side Walls of the chassis and supporting the frame from the support member. The armature and one of the contacts extend through a slot in the support member and are positioned to permit actuation of the armature by the frame and consequent actuation of the one contact into engagement with the other contact. The coil is mounted on a flanged bobbin which is adapted to be locked into the upstanding side walls of the relay chassis.

Further objects and advantages of our invention may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a sectional view of the relay taken on line 11 of FIG. 2;

FIG. 2 is a plan view of the relay;

FIG. 3 is a side view of the relay; and

FIG. 4 is a perspective view of certain elements of the relay with portions thereof cut away for clarity.

FIGS. 1-4 show a relay having a chassis 1d of strong rigid material, such as steel, which will not yield appreciably upon any impact likely to occur in manufacture, shipment, or use. Chassis provides a pair of opposed 3,184,564 Patented May 18, 1965 upstanding side walls 11 and 12 integrally formed with a base 13. A bracket 14 is centrally secured to the chassis by means of projections 15 which engage the side walls 11 and 12 and by a bracket leg 16 which is spot welded to the base of the chassis. A T-shaped slot 17 (see FIG. 4) is provided in bracket 14 for accommodation of a relay armature 18.

Armature 18 is made from a material of high magnetic permeability, such as an iron alloy having 47% nickel, and is flat and rectangular in form to permit grinding or lapping the top surface to a truly fiat smooth condition. Armature 18 is copper-plated to create a nonmagnetic gap when assembled in the relay. A pair of notches 19 are formed in the longitudinal edges of the armature to lock the armature longitudinally in the lower portion of bracket slot 17. Armature 18 is designed to be approximately balanced with respect to bracket slot 17, but is oriented to the position shown in FIG. 1 by the upward bias of a spring arm 20 which engages a portion of the lower surface of armature 18 and passes through bracket slot 17 beneath the armature.

Spring arm 20 carries a relay contact 21 near its free end, being secured at its other end to the base of chassis 199 by a fastener 22. A second relay contact 23 is mounted on a short spring arm 24 and is positioned immediately below contact 21. Short spring arm 24 is secured in a recess of insulator 25 by rivet 26 and plate 26a, at the opposite end of the chassis base. Thus, in addition to insulating spring arm 24 from chassis 10, insulator 25 also orients the position of spring arm 24. Spring arms 2% and 24 are connected to terminals 27 and 28, respectively, to permit the connection of the relay contacts in an electrical circuit.

In order to actuate armature 18, a U-shaped core or frame 29 and a coil 30 wound on a form or bobbin 31 are provided. Two or more terminal leads 3dr: may be provided for coil 39. Frame 29 is of highly permeable magnetic material similar to that of armature 18. The frame is disposed on the relay in an inverted position, having one leg 29a secured to bracket 14 by suitable fasteners 32 and the other leg 2% depending downwardly through the axis of coil 30.

Bobbin 31, on which coil 30 is wound, is made of insulating material, preferably nylon, and provides a generally rectangular flange 33 on its lower end, having rounded or cutaway corners for securing the coil to chassis 10 independently of frame 29. This is accomplished through the proper dimensioning of flange 33 to be approximately equal in width to the transverse dimension of the chassis and through the use of opposing T-slots 11a and 12a formed in the upstanding side walls 11 and 12 of the chassis. The rectangular base flange of the bobbin is initially engaged with the slots in the chassis side walls, following which the bobbin is rotated into locking engagement with the chassis. It can be seen that upon the application of an electrical current to leads 30a of coil 3%) an electromagnetic force is induced in frame 29 to draw the end 18:: of the armature upwardly into contact with the coil-enclosed leg 2% of the frame.

An adjusting screw 34 is provided to vary the air gap between armature 1% and leg 2% of the frame, thereby controlling the amount of current necessary in coil 30 to actuate the armature to the closed position. A second adjusting screw 35 is provided to vary the vertical position of spring arm 24 to control the force between contact 21 and contact 23 when the relay is closed. An insulator strip 36 is secured to rivet 26 to overlay the lower surface of spring arm 24, thereby insulating arm 24 from adjusting screw 35.

As can be best seen in FIG. 2, a hair spring 37 is positioned between armature 18 and spring arm 20. One arm 38 of spring 37 provides an upwardly turned end area,

38a (see FIG. 1) which extends upwardly through circular aperture 39 in the armature. The other arm 40 of the hair spring 37 provides a downwardly turned end ttla (see FIG. 3) which engages a notch 41 in the side of the spring arm. The purpose of this assembly is to exert a constant sideways pull and a clockwise rotative force (as viewed in FIG. 2) on armature 18 to insure that the armature will always close against the frame at exactly the same position. This action provides for the drop-out of armature 13 upon the dropping of the current to a single predetermined value on repeated operations of the relay. When hair spring 37 is arranged as shown in FIG. 2, it biases its end of the armature toward chassis side wall 12.

The manner of assembling the relay is as follows. After the securing of bracket 14 and spring arm 24 to base 13 of the chassis, spring arm is inserted through slot 17 in the bracket and is also secured to base 13. Armature 18 is then inserted through the wider portion of bracket 17 and, upon alignment of armature notches 19 with the bracket edges defining the lower portion of bracket slot 17, the armature may be slid downwardly in the slot until it rests upon the upper surface of spring arm 20.

Coil 3t] and its supporting bobbin 31 is then lowered diagonally into the chassis until diagonally opposite corners of flange 33 rest upon the upper surfaces 11b and 12b of T-slots 11a and 12a in side walls 11 and 12. Bobbin 31 is then locked into side walls 11 and 12 by rotating the bobbin until the sides of bobbin flange 33 lie parallel to the sides of the chassis and are secured in the T-slots of side walls 11 and 12. Of course, the coil is so oriented as to receive one leg of the frame 29 through its axis.

Frame 29 is then lowered so that leg 2% is surrounded by coil and the other leg 29a is juxtaposed bracket 14- and is subsequently fastened thereto by fasteners 32.

In the assembled position, spring arm 20 biases armature 18 upwardly against leg 29a of frame 29. Thus, the motion of armature 18 is pivotal about the lower surface of leg 2% of the frame. This leg also prevents the armature from becoming separated from bracket 14 in that it depends below the wider portion of bracket slot 17 (see FIG. 1). Furthermore, it can be seen that the rotation of coil 30 is restricted by its relationship with leg 29!) of frame 29. Ideally, the relay may be placed in a housing having walls tightly fitted against the outer surface of side walls 11 and 12 to thereby prevent rotation of coil 3-11. This would preclude the possibility of a rotative force on frame 29.

The relay is operated upon the application of suflicient current to coil leads 30a to thereby induce an adequate electromagnetic force in frame 29 to pick-up armature 13 and consequently lift lower end 18a of the armature into engagement with leg 2% of the frame. This action provides a pivoting of the armature about the lower surface of leg 2% of the frame, resulting in the lowering of contact 21 into engagement with contact 23 to complete the circuit through the relay. It can be seen that the adjustment of screw 34 upwardly to decrease the air gap between the armature 18 and leg 29!) of the frame decreases the amount of current necessary to pick up the armature. It can also be seen that the adjustment of screw upwardly increases the upward force of contact 23 on contact 21 and thus on the right end of the armature when the contacts are closed. This requires a greater holding force between frame 29 and end 18a of the armature and consequently a higher current value in coil 30 to maintain contacts 21 and 23 in the closed position. Thus, the upward adjustment of screw 35 increases the current value at which the relay drop out will take place.

The twist-locking support of relay coil 34) and bobbin 31 in side walls 11 and 12 of the chassis, independently of the mounting of frame 29 to bracket 14, eliminates any stresses which might be placed on frame 29 by the coil upon dropping or other impact against the relay. This assures accurate alignment of leg 2% of the frame within the coil 30, as well as accurate matching of the legs of frame 29 to flat-surfaced armature 18. These characteristics permit regular, dependable operation of the relay at predetermined current flow, such current flow for opening and closing of the relay being adjustable by screws 34 and 35. The constant relationship of armature 18 to frame 29 is further assured by the action of hair spring 37. This invention thus provides a compact dependable relay capable of withstanding substantial impacts without detrimental effect upon the electrical characteristics of the relay.

While we have shown and described a specific embodiment of our invention, we do not desire our invention to be limited to the particular construction shown and described. Instead, we intend, by the appended claims, to cover all modifications within the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A relay comprising:

(a) a chassis providing a base and a pair of rigid upstanding side walls;

(b) a pair of relatively movable switch contacts supported by said chassis;

(c) an armature movably supported by said chassis for actuating one of said contacts;

(:1) a magnetic frame positioned adjacent said armature to form a magnetic circuit therewith;

(e) a bobbin secured to the side walls of said chassis;

(f) a coil mounted on said bobbin for providing an electromagnetic force to said frame to magnetically attract said armature;

(g) means for supporting said frame from said chassis independently of said coil.

2. A relay comprising:

(a) a chassis providing a base and a pair of opposed upstanding side walls, each of said side walls having a slot therein;

(1)) a bracket secured to said chassis;

(c) a pair of relatively movable switch contacts supported by said chassis;

(d) an armature movably supported by said chassis for actuating one of said contacts;

(e) a coil and bobbin therefor, said bobbin including a flange engaged in said slots to support said coil from said chassis;

(f) a magnetic frame having a portion thereof extending through said coil and positioned adjacent said armature to form a magnetic circuit with said armature;

(g) means for securing said frame to said bracket for supporting said frame from said chassis independently of said coil.

3. A relay comprising:

(a) a chassis providing a base and a pair of opposed upstanding side walls, each of said side walls having a T-shaped slot therein;

(12) a pair of relatively movable switch contacts supported by said chassis;

(c) an armature movably supported by said chassis for actuating one of said contacts;

(d) a magnetic frame positioned adjacent said armature to form a magnetic circuit with said armature;

(e) a coil bobbin having a rectangular flange, said flange being dimensioned for diagonal reception between said T-shaped slots for locking engagement with said side walls upon angular rotation of said bobbin;

(f) a coil wound on said bobbin for providing an electromagnetic force to said frame to actuate said armature;

(g) means for supporting said frame from said chassis independently of: said coil.

4. A relay comprising:

(a) a chassis providing a base and a pair of upstanding side Walls;

(1)) an upstanding bracket having a slot therein secured to said chassis;

(c) a pair of relatively movable switch contacts supported by said chassis, one of said contacts being carried by a spring arm which extends through said bracket slot;

((1) an armature extending through said bracket slot and pivotal therein to actuate said spring arm; (0) a magnetic frame positioned adjacent said armature to form a magnetic circuit with said armature;

(1") a coil bobbin secured to said chassis;

(g) a coil Wound on said bobbin, said coil being adapted for connection to an electrical power source to provide an electromagnetic force to said frame for pivoting of said armature in said bracket slot;

(h) means for securing said frame to said bracket for support from said chassis independently of said coil.

5. The relay recited in claim 4 wherein said armature overlies said spring arm and wherein said spring arm normally biases said armature to its inoperative position.

6. A relay comprising:

(a) a chassis providing a base and a pair of upstanding side walls;

(b) an upstanding bracket secured to said side Walls,

said bracket including means defining a slot;

(c) first and second contacts secured to said chassis and positioned for engagement on one side of said bracket;

(0') a resilient arm extending through said bracket slot and supporting said first contact;

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(0) a generally flat elongated armature extending through said bracket slot for pivoting therein and overlying said spring arm for actuating said first contact, said armature being normally biased to an inoperative position by said spring arm;

(1") a coil and a bobbin therefor, said bobbin being secured to the side Walls of said chassis; and

(g) a U-shaped frame having one leg extending through said coil and providing an air gap between said one leg and said armature on the other side of said bracket from said contacts, and a second leg secured to said bracket and engaging an intermediate portion of said armature whereby the flow of electrical current in said coil produces an electro-magnetic force in said frame to pivot said armature against the bias of said spring arm to thereby close said air gap and said contacts.

7. The relay recited in claim 6 additionally comprising means for biasing said armature against one edge of said bracket slot.

References ited by the Examiner UNITED STATES PATENTS 2,296,123 9/42 Stimson 317l98 2,440,888 5/48 Biggle 317 2,892,053 6/59 Lambert et a1 200-104 2,932,704 4/60 Dennison et a1 20087 2,991,395 7/61 Allen et al 317-5 3,036,246 5/62 Valleau 317158 3,050,703 8/62 Duescher 317-158 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. A RELAY COMPRISING: (A) A CHASSIS PROVIDING A BASE AND A PAIR OF RIGID UPSTANDING SIDE WALLS; (B) A PAIR OF RELATIVELY MOVABLE SWITCH CONTACTS SUPPORTED BY SAID CHASSIS; (C) AN ARMATURE MOVABLY SUPPORTED BY SAID CHASSIS FOR ACTUATING ONE OF SAID CONTACTS; (D) A MAGNETIC FRAME POSITIONED ADJACENT SAID ARMATURE TO FORM A MAGNETIC CIRCUIT THEREWITH; (E) A BOBBIN SECURED TO THE SIDE WALLS OF SAID CHASSIS; (F) A COIL MOUNTED ON SAID BOBBIN FOR PROVIDING AN ELECTROMAGNETIC FORCE TO FRAME TO MAGNETICALLY ATTRACT SAID ARMATURE; (G) MEANS FOR SUPPORTING SAID FRAME FROM SAID CHASSIS INDEPENDENTLY OF SAID COIL. 